Statistician Nate Silver predicted Barack Obama would win the 2012 presidential election in his FiveThirtyEight.com blog, which aggregates polls rather than relying on a single survey. Critics say media and pollsters put too much emphasis on the so-called “horse race” aspect of election campaigns and not enough on substance. (Getty Images/Bloomberg/David Paul Morris)

Smart phones, social media and the Internet have made it easier than ever for people to make their views known, but the new technology can make it harder for political pollsters to gather and measure public opinions with precision or consistency. They face public suspicions of partisanship, reluctance to provide candid answers and — as cellphone use grows — difficulty reaching respondents by the traditional method of random calls to household landlines. Meanwhile, critics charge that the news media pay too much attention to “horse-race” polls showing who leads in political races and not enough to candidates' policy ideas. The 2014 elections, in which pollsters miscalled the results of a number of closely watched races, cast a harsh spotlight on the industry, but pollsters contend their record has improved over the years. Some experts see promise in the increasing use of “opt-in” polls such as those on the Internet, but the approach is controversial.